of chicago



March 19, 1929. J. M. LARSON 1,705527 APPARATUS FOR CONTROLLABLY. REGUL'ATING TEMPERATURE Fi-led Oct. 8, 1926 5 in ammwm y Patented ltlar. l9, lgalilu =1; stair Jennie. season, or orrroaeo, ILLINOIS,

ASSIGIIOR T0 NATIONAL REGULATOR 00.,

OF CHIOAGU, ILLINOIS, A CORPORATION OF ILLINOIS.

APPARATUS FOR CONTROLLABLY REGULATING TEMPERATURE.

Application filed October 8, 1926. Serial No. 140,231.

This invention relates toapparatus for controllably regulating temperature, and more specifically concerns combined thermostatic control ofair conditioning and circulating ap paratusand of heat-radiating units.

In providing for the automatic regulation of room temperature, it is important that proper allowance anc provision be made for the introduction and circulation of fresh air during'both moderate and extreme weather conditions, and a most important object of this invention is to provide means which may be conveniently adjusted or set at a selected thermometric degree; which will operate automatically to control a combination of individually controllable elements, in a novel manner to be described, to therebycfiect and maintain the room temperature substantially uniform at the degree for which it is set and, at the same time, effect and regulate the conditioning and circulation of fresh air; which will so operate with a sufiiciently wide 7 range of controllin effects as to automatically allow and provide for radical changes in weather conditions and out-door temperature; and which is so constructed that it may be readily taken apart and re-assembled, if desired, for inspection or repairs, or for any other reason.

In the drawings, Figure l is a vertical sectional view of an adjustable compound thermostatic controller constructed according to this invention;

Fig. 2 is a horizontal view of-one end-member serving as the base of the controller, taken upon the line 22 of Fig. l and Fig. 3is a somewhat diagrammatic view il lustrating the controller of F 1g. 1 controllably connected with an automatically adjustable air conditioning and circulating unit, which is shown in vertical section, and with an'automatically controllable-supplemental or auxiliary heat-nidiat-ing unit, shown in elevation.

Thermostatically controlled heating systems are well known and, for obvious reasons, the type of such systems generally preferred embodies means for automatically controlling the admission of fresh, warmed'air. Although some systems of this type'possess many desirable qualifications, they do not usually operate satisfactorily under radical s in weathe conditions, 'Where the Le v'sens 3111115 ditions, a substantially uniform room temperature, their range of control is considerably limited and, due to the very principle upon which they operate, they are incapable of con tinuing to maintain the desired room temperature and at the same time provide a proper circulation of fresh air during abnormal weather conditions.

It is obvious that, during extremely cold weather, the admission of the colder fresh air requires a counter-acting increase in the heating facilities, if the admission and circulation of fresh air is to continue and the desired room temperature is to be maintained. These previously known systems operate, however, to automatically shut off the admission ofoutdoor air as the room temperature decreases, with the consequence that, during abnormally cold weather conditions, the circulation of fresh air is at first considerably restricted and finally i entirely discontinued.

New, it is also obvious that, if the room should be provided with additional heating facilities, they could be temporarily employed to assist in maintaining the desired room temperature and thereby allow a proportionately greater amount ofthe cold fresh air to be admitted. Manual adjustment of such additional heating facilities would require more 7 or lessconstant attention, however, and it would be practically impossible, even with such attention, to so re 'ulate-them as to counteract the out-door changes in temperature with any bility as would insure the proper and satisfactory automatic regulation of the admission and circulation of freshair.

This invention contemplates the use of such additional heating facilities and provides for their automatic control in direct combination with theautomatic control of the conditioning and circulation of fresh air. An adjustable compound thermostatic controller is provided for the combined control of one or more automatically adjustable air conditioning and circulating units and of one or more automatic-ally controllable supplemental or auxiliary heat-radiating units, one each of such units being illustrated in the drawings. Under normal or moderate weather conditions, wherein the thermostatic control I of the air conditioning and circulating units is alone sufficient to maintain the desired iomntemperature ar' 1 fresh air "ulation,

such decree of uniformit and reliaunits will not be required or employed, and a sensitive and graduated adjustment of the air conditioning and circulating units will obtain. Howev er, the construction and operation of the compound thermostatic controller is such that a slight decrease in room temperature below the thermometric degree at which the controller is set will cause the supplemental or auxiliary heat-radiating units to be brought into service, and such service will be continued as long as required to assist the air conditioning and circulating units in restoring and maintaining room temperature. At

the same time, the aforesaid sensitive and sist, so that the regulated conditioning and circulation of fresh air may be continued during radical changes in weather conditions and out-door temperature.

In order to give a better understanding of the purpose and use of the compound thermostatic controller, it may be well, before describino its construction and operation, to describe the auton'iatically' controllable elements which. are connected therew1th and controlled in operation thereby. I

teferrl'ng, first, to Fig. 3, 1t w1ll be seen that the air conditioning and circulating unit therein shown comprises a casing 1, the interior of which is divided into two communicating chambers, 2 and 3. The output chamber 2 constitutes a .mixing chamber into which heated and unheated fresh air is introllably delivered from the intake char oer 3, and from which the thus conditioned fresh air passes into the room through the output opening 4. The intake chamber 3 is provided with a cold or fresh air inletligand houses a l'leat-rruliating unit 6 and an electrically driven suctioi'i-fan 7. in the drawings, the unit (5 represents a steam heated radiator, but, while this type of unit is pi'efcrrrah a hot water or electrically heated" unit could be used equally well in many instances. The purpose of the fan 7 is to provide a forced draft, when desired.

Dampers 8 and 9 are shown as pivotally supported at 10 and ll,respectively, and are 'operatlvely connected toeach other, by the link 12, and to the operating lever 13 a fluid-pressure motor 1 1, by the link 15. 11

spring 16 acts upon lever 13 to oppose the movement thereof by the expansion of motor 14. The motor 14; is connected to be controlled in operation by the compound thermostatic controller '17, through the controlconduit 18. Damper 8 controls the amount of air which is allowed to pass from ehan'iber 3, through the heat-radiating un1t 6, into chamber 2, and damper 9 controls theamount of air which is allowed to be bypassed around said unit 3, from chamber 3 into chamber 2. It will thus be seen that, with this arrangement, the-adjustment of dampers 8 and 9 will control the mixture of heated and unheated fresh air delivered from. the intake chamber 3 to the output chamber 2 and thence into the room through opening l. In order to provide for a constant circulation of ap proximately the same volume of conditioned fresh air, dampers 8 and 9 are herein shown as so connected together by link 12 that, when damper 8 is \ide open, damper 9 will be completely closed, and vice versa, but it is within the scope of this invention to so are I range or connect them that either may be wide open before the other begins to close. Furthermore, the relative sizes of the dampers may be different.

A separately placed, supplemental or auxiliary heat-radiating 'unit 19 is herein shown as a conventional steam heated radiator, but another type of heat-radiating unit'could be substituted, if preferred. 'lhe'supply of the heating medium to this unit 19 controlled by a fluid-pressure motor located within the housing 20, which motor may be similar in construction and operation to the motor l l. This motor for controlling the supply of the heating medium to the heat-radiating unit 19 is connected to be controlled in operation by the controller 17', through the control-com duit21.

It 1s to be understood that, while but one air conditioning; and circulating unit-and but one supplemental or auxiliary heatq'adiating unit are here1n shown, such a showingis for illustrative and explanatory purposes only.

units may be controlled by a single compound thermostatic controller.

It has been mentioned that the heat-radr:

ati'ng unit 6 represents asteam heated radiator and that the purpose ofthe fan 7 is to pro .vide forced draft, whendesired. Inaddi ice connections to these elements, and they t t sion of the motor within ho SIHQ' 're-oin through output opening 4;

are not shown.

The operation. of the parts thus t'ar dcscribed is as follows. Alternate supply and release of fluid-pressure through conduits l8 and 21 will effect the corresponding expair sion and collapse of motor 1% and the motor within housing 20,respectively. Such supply and release of fluid-pressure throughsaid conduits is automatically controlled y the compound thermostatic controller 17 in a manner to be presently described, it being sutlicient at this point to state that, when the controller 1'? has been set to etlect and maintain a desired degree often'iperature, the automatic controlling operation thereoi is such that decreases in temperature slightly below said degree will occasion a proportionately gradual increase in the supply of fluid-pressure to conduit. 18 and, if such decrease in temperature continues to a predetermined further degree, iiui l-pressure will he released from conduit 21. Conversely, if the temperature should increase slightly above the degree for whic-h'the controller has been set, a proportionately gradual decrease in tne supply of fluid-pressure to conduit 18 will occur and,

if such increase in temperature continues to a predetermined further degree, fiuid-pressure will be supplied to conduit 1. The drawings show the motor 14 as collapsed and it is to be assumed that the motor within housing; 20 is expanded. Dampers 8 and 9 areshown positioned sothat the air conditioning and circulating unit will operate to supplythe maximum amount of cool fresh air, and it is to he understood 20has ef- 't'ected the shutting on or the heatin nediuin from the supplemental unit 19. so

that it is not in service. When the emperature of the room has decreased to a'predetermined detluid- 'iressnre will be gradually'sup plied. as at'oresaid, to conduit 18, and, motor 14: will begin to'be expanded thereby, moving lever 13. against the opposition of spring); 16, to effect an. opening movement oi damper 8 and a closing movement of damper 9, through links 12 and 15, respectively, thus increasing the amount of air passed hetwcen the coils of. heat-radiating unit .6 and decreasing the amount of air lay-passed around nit into-chamber 2, and thence outwardly into the It, notwithstanding this automatic increase in the amount of heats" air supplied hy the ditioning a. i

5 L r unit, M

the expanploying a is efiected gradually ture of the room continues to decrease, fluidpressure will be released, as aforesaid, from conduit 21, and the motor within housing 20 will collapse and permit the supply of the heating medium to the supplemental unit 19, and such unit will thus be brought into service to assist in the heating of the room. The collapse of the motor witnin housing. 20 may be assisted by a spring (not shown) acting in a manner similar to the spring 16, but, where a steam heated radiator is employed, as shown here, it may be ei'lected by the valve-opening pressure or the steam in the supplypipe.

It is needless to describe, in detail, the return of the several parts to their positions as shown in the drawings, itv being sulllcient'to explain that, when the temperature of the room has increased to a predetermined degree, fluid-pressure willbe automatically released in the same gradual manner with which it was hei er supplied in conduit 18 through the operation of controller 17, and motor 14 will begin to collapse, such colla being assisted by the action of spring 16, and the hereinbe'fore described movement of dampers 8 and-9 will be reversed, so that the amount of heated air delivered into chamber 2 and into the room will be decreased, while the amount of unheated air, by-passed around the heatradiating' unit 6, will be increased. If the temperature of the room continues to increase, fiuid-pressure will again be suppliedto conduit 21, and the motor within housing 20 will again be expanded and shut off the su, ply of the heating medium to supplemental unit 19, dispensingwith its previously required assistance.

l Vhile, as hereinbet'ore stated, the employment of the fan 7 may be optional and does not term a part 01. this invention, it may be well to direct attention to the factthat the etii i ncy of the air conditic ling and circulating unit maybe augmented thereby. Both the air-heating and air-cooling functions of the unit may be materially increased by eniforced draft. Furthermore, should the direction of the wind be such as to interfere with the proper intake of fresh outdoor air, the suction tan could be used to correct such a condition.

Referring, now, to Figs 1 and 2, the compound thermostatic controller therein shown the element indicated at 17 in Fig. 3. ll; comprises a single therinostatically actuated valve 22 which' controls the Supply and release of fluid-pressin'e to and from the two individual control-conduits 18 and 21. FlHlCl-DTGSSUIG is supplied to the controller, through a supply conduit 23, from a source (not shown} which may 3e suitably constructed and located as preferred. Although the supply and release of fluid-pressure to and from the two conduits 18 and 21 is by the single valve 22, such supply and re respect 7 motor within housing 20, connected with conduit 21, will Le.correspondingly completely collapsed and completely expanded, without such graduated and proportioiuite movement, whenever the respective decreases andincreases in room temperatures reach predetermined degrees. V

. An end-member, herein shown as a base 24, is provided with cars by which the con troller is secured in position, neferably upright upon the wall of the room at a point distant from the air conditioning and circulating units andthc heat-radiating units which it is designed to operatively control. Supported upon base 24 is a tube of me.- te ial possessing a high coeiiicieht of expansion. Tube 26 is internally threaded at each end-part thereof, one end being screwed upon a boss 27 of base 2 1 and the otherfitted with an end-member, herein shown as a screw-plug 28, having a centrally arranged threaded orilice fitted with an adjusting; screw Any preferred means may be employed for adjusting the screw 29. As herein shown, the upper end-part of the screw is squared and operatively engaged by a circular wrench-plate 30, andwrench-plate 30 is provided with a pair of upstanding pins 31 which project through corresponding apertures in superposed cap, or adjusting plate 32- 32 is formed with a depending annular fla e '33 suitable to be engaged by the fingers for preferably formed of mater al posses low co-ehlcient of expansion. rigidly supported by base 24 tGjflOjGCi] upadjustment and provided with. a thermometric scale tobeused for setting the controller for eperationat diiierent desired degrees of temperature. I p Thelower end of screw 29 is cupp'ec to receive the upper pointer end of a re wardly within tube 26, and the upper endpart of this post is provided with a socket which receives the lower on l-part of an eaten ,SlOll-POSl) 37, removably lined in pOSlli-lilll by the pin 38-. Secured to the upper end o'l extensionpo'st 37, by t ie that spring connec ion 39, is a short laterally extending: lever lO, to the free end of which the depending valve 22 is connected by another flat spring connection ll. Between its ends, the upper surface of lever 40 is provided with acup w receives the lower pointed end of therod 353. A guiding flange, such as the disc or spider d3 upon rod 35, facilitates the replacement oi the upper pointed end of the rod in the screwcup 34, if for any reason the tube 26 has been unscrewed and removed from base 2 1-, or the plug 28has been removed from the tube.

Pie e.

sing a Changes in temperature will ell'ect the longitudinal contraction and expansion of the tube 26.- As viewed iii-Fig. 1, contraction of the tube, which will be occasioned by a oecrease in temperature, will draw plug 28'toward base 24:, for ing'rod downwardly upon lever and thereby flexing spring connection 39 and moving valve 22 to cover the port 44. Conversely, expansion of the tube 26, which will be occusioned'by an in crease in temperature, will move plug 28 away from base 24%, the downward pressure of rod upon lever 40 will be gradually withdrawn, and spring'c'onnection 39 will 'aise lever 40 and move valve 22 gradually away from the port all. The purpose of the flexible spring connection 41, by which valve 22 is attached to leve i'-O, is to pc unit a turther contraction of tube 26 and movement ot the intern'ledii-i-te parts'to take place after valve 22 has been closed, without damage to, or disarrangeinent of, any of the connections. Under ideal working conditions. valve 22 will be maintained in a stateot floating equilibrium over port 44:, acting to control the ainount of fluid-pressure allowed to escape therefrom and thus govern the degree of fluid-pressure supplied to conduit 18in a manner to be presently more fully explained.

lVithin base. 25 there is adownwardly opening, stepped, cir'ci1lal',recess' l5, which is closed by a centrally aperture-d screw-plug 16.

A diaphragm 47 is tightly clamped byth'e spider-air d8 upon an annular step or shoulder or the recess and divides it into two-concentric chambers, ill-and 50, which are re speetiv'ely connected by control-ducts 51 and with conduits 18 and 21 (see Fig. 2). The central aperture 53 in screw-plug V 46 leads from chamber tothe outer air and is controlled bya valve 54, which is formed with a slotted head and a threaded stein justably' secured'to the diap agnu 47, said stein being screwed into pair or collars bearing tightly a ainst opposite sidesofsaid diai A cylindri J coiled spring-55 is arranged around the i alve-stein and bears upwardly beneath a shoulder on the lower to raise one 01" said pair of collars, act

(liapl'iregni on hold valve normally .nd isad closed over aperture 53. It is'to be noted v duct 63. Outlet duct .62 leads to port 44,:

l urthcinmre, the entire valvc- V sages, and to chamber 49 and conduit 18, will not equal the amount which valve 22-, when fully open, will allow to escape from port and thence, through outlet duct 67, to the outer air, and needle-valve G1 is likewise designed to be adjusted so that the amountoi fluid-m'essure permitted by it to pass to itsrespective duct and passage, and to chamber and conduit 21, will not equal theamouut which valve 54, when fully open, will allow to escape from outlet aperture 53 to the outer air.

The position of the parts as shown in the drawings indicates that the temperature oi the room is slightly above the degree for which the thermostatic scale on the plate 32 of the controller 17 has'been adjusted or set, with the result that tube 26 has expanded sufficiently to allow the movement of valve 22 to fully open port 44. Upon the supply of fluid-pressurethrough supply conduit 23 to supply-duct 57, a limited amount will pass needle-valve 61, through passage 59 to chamber 50, and thence through control-duct 52 to conduit 21. Valve 54 being held'closed over the outlet aperture 53 by the action of spring 55, fluid-pressure will accumulate 1n chamber 50 and act upwardly upon diaphragm 47 to assist .spring 55 in holding valve 54 in such closed position. Fluid pressure will also accumulate in control-duct 52 and conduit 21 and act upon the motor in housing 20 (Fig. 3) to shut-oilthe heating medium from the supplemental heat-radiating unit 19, the speed with which said motor is expanded by the accumulating fluid-pressure being determincd by the adjustment of needle valve 61.

This pressure will be built up in the cham ber 50 regardless of the fact that the outlet 44 may be open for the reason that the passage 59 branches off tromthe passage 57 ahead of the needle valve 60. The needle valve 60 prevents any appreciable diminution of pressure in the passage 57 due to the opening of the port 44.

A limited amount of fluid-pressure will also pass needle-valve 60, through passage 58, outlet-duct 62, passage 64, and outlet 65, to the open port 44, and from thence into tube 26 and through outlet-duct 67 to the outer air. lVith port 44 fully open, the fluid-pressure thus passing needle-valveGO will escape to the outer air, and there will be no accumulation of pressure in' control-duct 63 and chamber 49, nor will there be any accumulation of pressure in control-duct 51 and conduit 18. Consequently, motor 14 (Fig. 3) will remain collapsed, hot-air damper 8 will be closed and by-passdamper 9 will be open, all as shown in the drawings. It is therefore evident that,with the apparatus in service, when the temperature of the room has increased slightly above the desired degree, tube 26 will have expanded sufficiently to r'ully open port 44, and the ellect thereof upon the automatically controllable devices connected with conduits 18 and 21 will be to hold the supplemental heat-radiating unit 19 out oi service, and to place the air conditioning and circulating unit in its maximum air-cooling condition, excepting, of course, that the tan 7 may be employed to increase the intake and circulation of cool, fresh air.

The temperature of the room will now begin to decrease, tube 26 ot' the controller will correspondingly contract, and valve 22 will be thereby moved to gradually restrict the port 44. When this restriction reaches the point at which less fluid-pressure is al lowed to escape, through port 44, from passage 58 than is being admitted to said passage past the needle-valve 60, pressure will begin to accumulate in said passage and also in outlet-duct 62, chamber 49, control-duct 51, and conduit 18. The first effect of this accumulation of pressure will be to begin the expansion of motor 14 and, consequently, the opening movement of hot-air damper 8 and the closing movement of by-pass damper 9: It the resultant increase in the amount of heated air circulated by the air conditioning and circulating unit does not arrest the decrease in room temperature, and the tube 26 continues to contract and further restrict port 44, such further restriction will effect a further increase in the degree of accumulated pressure and motor 14 will be further expanded, against the opposition of spring 16, and dampers 8 and 9 will be correspondingly further adjusted. This graduated and proportionate adjustment of the dampers of by supply-conduit 23 and motor 14 will have accomplished the "full opening of hot-air damper 8 and the complete closing of by-pass damper 9.

The pressure which has been accumulating in conduit 18, with the aforesaid effects upon the dampers of the air conditioning and circulating unit, has been acting in chamber 49 with an increasing downward pressure upon diaphragm 4'7 but, until port 44 is almost or completely closed (dependent upon the adjustable resistance of spring 55), the escape of fluid-pressure is present in chamber 50.

chamber 50.

of fluid-pressure. therethrough has prevented sulficient accumulation Of pressure in cham her 49; to move the diaphragm against the combined opposing effect of spring 55 and the full degree of accumulated pressure in It may here be explained that spring 55 is powerful enough to hold valve 54 closed over outlet aperture 53 when there isno pressure in chamber 59, but would not alone be capable ofmaintaining it closed as the pressure accumulated in said chamber and acted downwardly upon the valve to force it open. However, diaphragm47 is attached to the valve-stem and the area of the diaphragm is so much greater than that of the aperture 53 that the valve-closing effect of the pressure in chamber upon the diaphragm'is far greater than the valve-opening effect thereof uponthe valve itself, and-the presence of any pressure whatever in said chamber therefore acts. to assist to a far greater degree than it opposes the action of spring in holding valve 54 closed. 7

It has been mentioned that the full degree Now, when the pressure in chamber 49 has accumulated to the degree at which its downward action upon the diaphragm 47 plus the downward action of the pressure in chamber 50 upon valve 54 exceeds the opposing effect of the upward action upon. said diaphragm of said pressure in chamber 50 plus that of spring 55, the valve will'begin to open. hen valve 54has thus been opened far enough to allow more fluid-pressure to escape, through" outlet, apertures 53, "from chamber 50 than is being admitted to said chamber past the needle-valve 6,1, the pressure in chamber 50 will be so weakened thereby that the accumulated pressure in chamber 49 will thereupon accomplish the full opening of the valve and the release of fluid-pressure from chamber 50 and from conduit 21. I

The release of fluid-pressure from conduit 21 will permit themotor in housing 20 (Fig. 3) to be collapsed, in the manner already describcd, to admit the heating medium to supplemental unit 19, and both the air condi- 1 tioni-ng and circulating unit and the supplemental or auxiliary heat-radiating unit will then be act ng at their maximum capacities to increase the room temper, ture. Attention is directed tow the fact that the introduction and circulation of fresh air throughout the gradual and proportionate adjustment of the dampers of the air conditioning-and, circulating unitand still continues after the supplemental heating facilities have, been brought into service.

The operation of the apparatus from its maximum temperature-reducing to its maxi mum temperature-increasing conditions having been de cribed, it. is hardly necessary to explain-the reverse operation of said zip-para continues,

gree, the apparatus first acts to arrestsuchf decrease by automatically effecting a gradual. and prop. rtionate adjustmcnt ot the airdampers of the air conditioning and circu lating unit, and that it is only when such adjustment proves inadequate to meet the requirements that the supplemental or aux: iliary heat-radiating unit is brought into service. It has also been mentioned that such service will be continued as long as required to assist in restoring and maintaining the'desired room temperature. Now,'with the additional room-heating facilities in service, the temperature,will be materially increased, but it does not follow that the assistance thereof should be dispensed with as soon-as this result is broughtabout, since it has already.-

been automatically determined that theheatproducing qualifications of the air conditioning and circulating unit are not alone suflicient toarrestthe decrease in room temperature, and itremains to be determined whether or not they are sufficient to maintain'the desired temperature when again restored.

Returning, now, to the description and operation of the apparatus, and assuming that valve holds port 44- completely closed, so that the "full power of fluid-pressure is present in chamber 49 and conduit 18, while valve 54 is fully open, so thatthere is no accumulated pressure in chamber 50 and conduit 21,

letit be further assumed that the combined heating effects of the air conditioning and circulating unit and thesupplemental unit 19 are causing the room temperature to be increased. As tube 26 expands with such increase in temperature and as valve 22 is thereby gradually moved to open and in crease the opening of port 44, the gradual increase in the amount of fluid-pressure thus allowed; to escape progressively weakens the pressure which is present in chamber 49 and conduit 18. The first effect of this reduction of pressure will be to begin the collapse of motor 14 and, consequently, the closing moven'ient o't' hotairdamper 8 and the opening movement of by-pass damper 9.. At the same time, of course, the downward pressure exerted upon diaphragm 47 will be correspondingly reduced but, with valve 54 open, the

pressure cannot accumulate in chamber 50 and act upwardly upon said'diaphragm, and the result is that spring is the only active force seeking to close valve 54. Spring 55 is not powerful enough to eilectthe closing of valve 54, however, long as such action is opposed to any substantial de ee by the downward action of thepressure in chamber 49 upon the diaphragm 47. As a consequence, the motor in housingQOv (Fig. 3) will remain collapsed and the supplemental unit/l9 remain in service while the dampers 8 and 9 of the air conditioning and circulating unit are being gradually and proportionately adjusted to arrest the increase in temperature and, in some instances, this adjustment will pro vide the desired degree of temperature and maintain it by slight damper re-adj ustments, without dispensing with the service provided by the additional room-heating facilities. Under such conditions, valve 22 would he maintained in the aforesaid state of floating equilibrium over'port 44; the pressure in conduit 18 would be such as to hold motor 14 partially expanded; and the pressure in chamber 49 would not become sufficiently reduced to permit spring 55 to eilect the closing of valve 54. In other instances, such, for example, if over-sized additional heating ,i'a-

cilities were in service," the temperature or the room would continue to increase and etfeet the continued opening movement of valve 22 and the corresponding air-cooling adjustment of the aforesaid dampers. At the period in such opening movement 01" valve 22 wnen the amount of fluid-pressure allowed to escape from port 44 is substantially equal to the amount permitted to pass needle-valve 60, the pressure in chamber 49 and conduit 18 will have been reduced to a degree which will permit spring 55 to close the valve 54 and which will have allowed the substantially complete collapse of motor 14. As soon as valve 54 isclosed, the fluid-pressure permitted to pass needle valve 61 begins to accumulate in chamber 50 and conduit 2i, as hereinbe'fore described, holding valve 54 irmly closed over outlet aperture and eiieeting the expansion of the motor in hous ing 20 and the shutting oil' of the heating medium to supplemental unit 19.

The latitude and efiectiveness of the graduated control obtainable through the automatic operation of the dampers 01 the air conditioning and circulating unit are designed to be such that valve 22 of the controller 17 will be normally maintained in a floating equilibrium, as aforesaid, over port 44, at some point between its fully open and itscompletelyclosed positions, whether the supplemental heating facilities are required and are in service or whether they are not required and are not in service; that is to say, the additional heating facilities will not be brought into service unless required and will not be dispensed with unless not needed, but

the e:-;pansion and in either event, upon effecting or dispensing with such service, the valve will be returned to a balanced lioating position over port 44 tocllect the graduated and proportionate control or the position of the dampers as aforesaid.

While have described but one embodiment of my invention, it is obvious that many modifications therein may occur to those skilled in the art, and I desire, therefore, that my invention be limited only by the scope of the appended claims and by the prior art.

1 claim:

1. A compound thermostatic controller raving a tiuidlnessure inlet and first and second fluid-pressure actuators, eparate ducts leading from said inlet to each of said actuators, and automatically actuable means operating, upon actuation in one direction, to increase the degree of fluid-pressure supplied to said first actuator and then decrease the degree of fluid-pressure supplied to said second actuator, and, upon actuation in the reverse direction, to decrease the degree supplied to said first actuator and then increase the degree suppliedto said second actuator. V

2. A thermostatic cont-roller comprising a thermally expanslble and contractible tube, a inen'iber secured to one end-part of said tube, a fluid-pressure supply-conduit and a'plurality of fluid-pressure control-conduits connected with said member, a supply-duct and a plurality of control-ducts in said member connected respectively with said supply-conduit and-said control-conduits, passages in dividually connecting said supply -duct with said control-ducts, individually adjustable means restricting the passage of fluidpressure from said supply-duct to each of said passages, outlet-ducts individually connected Wlbll a first and a second of said passages and terminating in first and second outletports, respectively, a first valve actuated by contraction of said tube to effect a proportionately graduated control of said first outlet-port, a second valve controlling said second outlet-port, a fluid-pressure actuable diaphragm operatively associatcd with said second valve, a chamber of which said diaphragm forms a flexible wall, and a passage connecting said chamber with said first of said passages.

3. A thermostatic controller com rising a thermally expansible and contractible tube, a member secured to one end-part of said tube, a tluid-pressure supply-conduit and a plurality of fluid-pressure control-conduits connected with said member, a supplyduct and a plurality of control ducts in said member connected respectively with said supplyconduit and said control-conduits, passages individually connecting said supply-duct with said control-ducts, individually adjustable means restricting the passage of fluidindividually connecting said sum l wvitb sai'dcont-rol-ducts, individually ad u st pressure from said supply-duet to each of said passages, outlet-ducts individually connected with a first and a second of saidpassages and terminating in first and a second outlet-ports, respectively, a first valve actuated by the expansion and contraction of said tube to etlect a proportionately graduated control of said first outlet-port, a secondvalve controlling said second outlet-port and normally holding it closed, a pressurechamber and a passage connecting it with plurality of fiuid-presstuie control-conduits a su pplyduct connected with said niei-nb and a pluralityof control-ductsin said member connected respectively with said sup-plyconduit and said cont:'ol-conduits, 1

able means restricting'tlie passage of fluid pressure from said supply-duct to each of said passages, outlet-ducts individually connected with a first and a second of said passages and terminatin in first and second outlet po-rts, respectively, a first valve actuated by the expansion and contraction of said tube to ct a proportionately graduated control of said first outlet-port, a second valve controlling", said second outlet-port, a pair of pressure-chaml and a fluid-pressure actuable dir-i iihragm forming a flexible wall between said pressure-chambers, said pressurechambers being individually connected with said first and second of said passages and said diaphragm being operatively associated with said second valve; whereby the operation of said secondvalve is influenced by the difi'er entials in. the'degrees of fluid-pressure existing in said first and second o'l said r 'sngesf 5. A thermostatic controller comprring a thermally'expans1ble and contractlble tube, a member secured to one end-part oil said tube,

a fluid-pressure supply-conduit and a plural-.

ity of fluid-pressure eontrol-comluits cornected with said member, a supply-duct and a plurality-of control-ductsv in said member connected respectively with said supply-con duit and said control-conduits, passages 1ndividually connecting said supply-duct with said control-ducts, individually, adjustable means restricting the passage of fluid-pressure from said supply duct to each of said passages, outlet-ducts individually connected witha first and a second of said passages and terminating in first and second-outlet ports, respectively, a first valve actuated by the expansion and contraction of said tube to effect; a proportionately graduated control of saidfirst outlet-port, a second valve controlling said second'outlet-port, a pair of pressure-obsmbers and a. fluid-pressure actuable diaphragm forming a flexible wall between said pressure-chanibers, said pressure chambers being individually connected with said first and second of said passages'andsaid diaphragm being opera ively associatedwith said second valve, and a spring located in one of said pressure-cha1nbers and acting upon said second valve to hold it normally closed over said s 'zond, outletport; whereby the "nulat-ion oi fiuid-pressure in said second of said passages will act upon said diaphragm I and thereby asist said. spring in holding said a second valve closed, and whereby the accumulation of fluid-l-n'essure in said first of said passages vill act upon said diaphragm to counteract the etlect thereupon of the fluid pressure in said second of said passages, and

aid second valve will be forced open against the opposition of said spring, 7

G. A thermostatic controller con'iprisin g, a iuid-p-ressure supplyconduit and a plurality of fluid-pressure control-conduits, a supplyduetand a plurality of con-trol-ducts connected respectively with said supply-conduit and said control-conduits, passages individually connecting said su )p-ly-duct with said econtroll-ducts, individually adjustable means restricting the passage of fluid-pressure from said supply-duct to each of said passages, outlet-ducts individually connected with a first and a second of said passages and terminatmg 111 first and second outlet-ports,respectively,a first valve controlled thermostatical- 1y to e-fiect a proportionately graduated control of said first outlet-port, a second valve controlling said second. outlet-port, a, fluid presure actuable diaphragm operativelyj associatcd with said second valve, a chamber otwhich said diaphragm forum a flexible wall, and a passage connecting said chamber with said first oi? said passages.

7. A thermostatic controller comprising a fluid-pressure supply-coiuluit and a plurality of fluidpressure control-conduits, a supply duct and a plurality of control ducts connected respectively with-said supply-conduit and said controlc nduits, passagesindividually connecting said supply-duct with said control-ducts, individually adjustable means restricting the passage-of fluid-pressure from said supply-duct to each of said passages, outlet-ducts individually connected With a first and a second of said passages and ter1ninating in first ands cond outlet-ports, respectively, a. first valve controlled thermostatically to effect a proportionately graduated con-. trol of said first outlet-port, a second valve controlling said second outletport and norlnally holding it closed, a pressure-chamber and a passage-connecting it with said first of r.

Cir

said supply-duct to each of said passages,

outlet-(blots individually connected with a first and a second of said passages and tern'iinating in first and second outlet-ports, re spectively, a first valve controlled thermostaticallyto effect a proportionately graduated control of said first outlet-port, a second valve controlling said second outlet-port, a pair of pressure-chambers and a fluid-pressure actuable diaphragm forming a flexible wall between said pressure-chambers, said pressure-chambers being individually connected with said first and second of said passages and said diaphragm being operatively associated with said second valve whereby the operation of said second valve is influenced by the difi'erentials in the degrees of fluidpressure existing in said first and second of said passages.

9. A thermostatic controller, comprising a fluid-pressure supply-conduit and a plurality of fluid-pressure control-conduits, a supplyduct and a plurality of control-ducts connected respectively with said supply-conduit and said control-conduits, passages individually connectingsaid supply-duct with said control-ducts, individually adjustable means restricting the passage of fluid-pressure from said supply-duct to each of said passages, outlet-ducts individually connected with a first and a second of said passages and terminating in first and second outlet-ports,respectively, a first valve controlled thermostatically to effect a proportionately graduated control of said first outlet-port, a second valve controlling said second outlet-port, a pair of pressure-chambersand a fluidpressure actuable diaphragm forming a flexible wall between said pressure-chambers, said pressure chambers eing individually connected with said first and second of said passages and said diaphragm being operatively associated with said second valve, and a spring located in one of said pressure-chambers and acting upon said second va ve to hold it normally closed over said second outletport whereby the accumulation of fluid-pressure in said second of said passages will act upon said diaphragm and thereby assist said spring in holding said second valve closed, and whereby the accumula on of fluid-pressure in said first of said passages will act upon said diaphragm to counteract the eli'ect thereupon of the fluidpressure in said second of said passages, and said second valve will be forced open against the opposition of said spring.

10. A thermostatic construction for controlling two fluid-pressure motors, comprismotor will be expanded and whereby when sa1d exhaust port is open sa1d pressure motor will be exhausted, a thermostatic valve for controlling said exhaust port, another exhaust port and a passage leading to the other pressure motor, both said other exhaust port and said passage being in communication with the other of said branch passages, whereby when' said exhaust passage is closed said pressure motor will be expanded and whereby when said exhaust port is open said pressure motor will be exhausted, and a motor device controlled by the pressure in said one of said branch passages for controlling the exhaust from the exhaust port for said other of said branch passages.

In witness whereof, I have hereunto subscribed my name.

JOHN M. LARSON. 

